Micro-actuators have been formed on insulators or other substrates using micro-electronic techniques such as photolithography, vapor deposition, and etching. Such micro-actuators are often referred to as micro-electromechanical systems (MEMS) devices. An example of a micro-actuator includes a micro-mirror device. The micro-mirror device can be operated as a light modulator for amplitude and/or phase modulation of incident light. One application of a micro-mirror device is in a display system. As such, multiple micro-mirror devices are arranged in an array such that each micro-mirror device provides one cell or pixel of the display.
A conventional micro-mirror device includes an electrostatically actuated mirror supported for rotation about an axis of the mirror. Conventional micro-mirror devices, however, must be sufficiently sized to permit rotation of the mirror relative to supporting structure. Increasing the size of the micro-mirror device, however, reduces resolution of the display since fewer micro-mirror devices can occupy a given area. In addition, applied activation energies must be sufficiently large to generate a desired activation force on the mirror.
Accordingly, it is desired to minimize a size of a micro-mirror device so as to maximize the density of an array of such devices as well as increase an activation force on the micro-mirror device as generated by a given activation energy while minimizing the activation energy needed to generate the activation, force on the micro-mirror device.